Pre-treatment for salicide process

A method for treating a silicon substrate having a surface, comprising:

• providing a pre-processing chamber, wherein the pre-processing chamber has first and second power supplies for sputtering argon therein, wherein the first power supply can provide the argon with a first bias, and the second power supply can provide the silicon substrate with a second bias;
• placing the silicon substrate into the pre-processing chamber;
• providing the first bias to the argon;
• providing the second bias to the silicon substrate;
• modifying the first bias and the second bias to sputter the argon to simultaneously dry clean and amorphize the substrate surface;
• forming a metal film on the amorphized substrate surface;
• performing an annealing step, so that the metal film is reacted with the substrate surface to form a metal silicide layer;
• and
• removing the metal film which is not reacted with the substrate surface.